The present invention relates to a reframe circuit in a synchronous multiplexing device and more particularly, to a reframe circuit which maintains in the in-frame state for a long period of time even though the error rate on a transmission line is high, and minimizes the time required to detect an out-of-frame state for regaining the in-frame state in the out-of-frame state, resulting in minimization of information loss of received, multiplexed data streams.
In a digitalized telephone and data transmission network, frame synchronization performance of multiplexing device including a switching system and a transmission system which construct the network is an important parameter on which data transmission quality depends. Frame synchronization performance of the sychronous multiplexing device mainly depends on the performance of the reframe circuit and the synchronization performance of the reframe circuit depends on data transmission rates, a frame repetition period, overheads for frame synchronization, line conditions, etc. Accordingly, any common reframe circuit providing frame synchronization performance satisfyingly to all the multiplexing devices has not yet been developed.